Process control method, data registration program, and method for manufacturing electronic device

ABSTRACT

A process control method and data registration program for a surface mount line includes retrieving printing quality data, mounting quality data, and soldering pass/fail data from a primary recorder, recording the printing quality data, the mounting quality data, and the soldering pass/fail data for each of the components in a secondary recorder, and determining whether the solder printer and the mounter need adjustment by using the data of the components which are associated with the soldering pass/fail data recorded in the secondary recorder by a computer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefits of priority fromU.S. patent application Ser. No. 11/956,951 filed on Dec. 14, 2007, andJapanese Patent Application No. 2006-338193, filed on Dec. 15, 2006; theentire contents of both of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a process control method, a data registrationprogram, and a method for manufacturing an electronic device, and moreparticularly to a process control method for a surface mount line formanufacturing an electronic device by packaging components on asubstrate, a data registration program used in this process controlmethod, and a method for manufacturing an electronic device using thisprocess control method.

2. Background Art

An electronic device is manufactured by packaging components on asubstrate using a surface mount line provided with a solder printer, amounter, and a reflow furnace. On the surface mount line, components aresoldered to the substrate by printing solder on the substrate, mountingthe components on the substrate, and then melting and solidifying thesolder. Conventionally, in such a surface mount line, the quality of theelectronic device is controlled by controlling the process condition ofeach apparatus constituting the line (see, e.g., JP-A 2004-249673(Kokai)).

The method of controlling the quality of a product by controlling theprocess condition of each apparatus is successfully applied to the casewhere the process condition has high controllability and the quality ofthe product depends almost only on the process condition such as in themanufacturing line for semiconductor devices. However, this method isnot successfully applied to the surface mount line. This is because, inthe surface mount line, the quality of the product (electronic device)greatly depends on the state of materials such as the quality of thesubstrate and the viscosity of solder paste in addition to the processcondition, and the process condition is not in one-to-one correspondencewith the quality of the product. For example, the viscosity of solderpaste varies with time after opening the container and with ambienttemperature and humidity. The mounting position accuracy also depends onthe type of components. Furthermore, the quality of the product may bedeteriorated by the inherent defect of the substrate. Hence, in thesurface mount line, accurate process control cannot be achieved bysimply controlling the process condition.

SUMMARY OF THE INVENTION

According to an aspect of the invention, there is provided a processcontrol method for a surface mount line including a solder printerconfigured to print solder on a surface of a substrate, a solder printinspector configured to inspect the printed solder and outputtingprinting quality data, a mounter configured to mount components on thesubstrate with the solder printed, a mount inspector configured toinspect a state of the mounted components and outputting mountingquality data, a reflow furnace configured to heat the solder to solderthe components to the substrate, and a soldering inspector configured toinspect a state of the soldering and outputting soldering pass/faildata. The process control method comprises retrieving the printingquality data, the mounting quality data, and the soldering pass/faildata from a primary recorder with the printing quality data, themounting quality data, and the soldering pass/fail data recordedtherein, recording the printing quality data, the mounting quality data,and the soldering pass/fail data for each of the components in asecondary recorder; and determining whether the solder printer and themounter need adjustment by using the data of the components, which areassociated with the soldering pass/fail data recorded in the secondaryrecorder by a computer.

According to another aspect of the invention, there is provided a dataregistration program for a surface mount line including a solder printerconfigured to print solder on a surface of a substrate, a solder printinspector configured to inspect the printed solder and outputtingprinting quality data, a mounter configured to mount components on thesubstrate with the solder printed, a mount inspector configured toinspect a state of the mounted components and outputting mountingquality data, a reflow furnace configured to heat the solder to solderthe components to the substrate, and a soldering inspector configured toinspect a state of the soldering and outputting soldering pass/faildata. The data registration program registers each of the data bycausing a computer to execute retrieving the printing quality data, themounting quality data, and the soldering pass/fail data from a primaryrecorder with the printing quality data, the mounting quality data, andthe soldering pass/fail data recorded therein, recording the printingquality data, the mounting quality data, and the soldering pass/faildata for each of the components in a secondary recorder; and determiningwhether the solder printer and the mounter need adjustment by using thedata of the components, which are associated with the solderingpass/fail data recorded in the secondary recorder by a computer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an electronic devicemanufacturing process in this embodiment;

FIG. 2 is a flow chart illustrating the operation of the surface mountline of this embodiment;

FIG. 3A illustrates the format of data recorded in the primary recorder,and FIG. 3B illustrates the format of data recorded in the secondaryrecorder;

FIG. 4 is a flow chart illustrating the operation of the dataregistration tool of this embodiment;

FIG. 5 is a flow chart illustrating the operation of the SPC tool ofthis embodiment; and

FIG. 6 is a graph showing a visualized example of process capability,where the horizontal axis represents operation shift, and the verticalaxis represents the amount of mounting displacement in the Y-direction.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the invention will now be described with reference tothe drawings.

FIG. 1 is a block diagram illustrating an electronic devicemanufacturing process in this embodiment.

As shown in FIG. 1, the electronic device manufacturing process 1 inthis embodiment is based on a surface mount line 2 for printing solder102 on a substrate 101 and packaging components 103 with the solder 102to manufacture an electronic device 104, and a process control system 3for process control of the surface mount line 2. The electronic devicemanufacturing process 1 may include a plurality of surface mount lines2. In that case, the process control of the surface mount lines 2 isperformed by one process control system 3.

The surface mount line 2 includes a two-dimensional barcode scanner 10,a solder printer 11, a solder print inspector 12, a mounter 13, a mountinspector 14, a reflow furnace 15, and a soldering inspector 16 in thisorder. Furthermore, the surface mount line 2 includes a conveyor 17 forconveying the substrate 101 between these apparatuses. The substrate 101is conveyed by the conveyor 17 and passes through each apparatus of thesurface mount line 2. Thus a plurality of components 103 are packagedthereon, and an electronic device 104 is manufactured.

A two-dimensional barcode (QR code) identifying the substrate 101 isprinted on the surface of the substrate 101. Furthermore, a plurality oflocations are defined on the surface of the substrate 101, and thecomponent 103 is packaged on each location. Each location of thesubstrate 101 is provided with a plurality of electrodes (not shown)corresponding to the component 103 to be packaged. The number ofelectrodes corresponding to each component 103 depends on the type ofthe component 103.

The two-dimensional barcode scanner 10 scans a two-dimensional barcode(QR code) printed on the substrate 101 to identify the substrate 101 fedinto the surface mount line 2. Then the two-dimensional barcode scanner10 outputs the scan result of the QR code. The solder printer 11 printspaste solder 102 on the electrodes formed on the surface of thesubstrate 101.

The solder print inspector 12 inspects the solder 102 printed on thesubstrate 101 by the solder printer 11 and outputs the inspection resultas “printing quality data”. For example, the solder print inspector 12is provided with an AOI (automated optical inspection system), whichmeasures the shape of the printed solder 102 for each electrode, andoutputs the result as numerical data. In an example, the solder printinspector 12 measures the height and volume of the solder 102 andoutputs the result as a set of numerical data along with datarepresenting the location of the inspected region.

The mounter 13 mounts a component 103 on each location of the substrate101. The mount inspector 14 inspects the state of the mounted component103 and outputs the result as “mounting quality data”. For example, themount inspector 14 is provided with an AOI, which measures the amount ofdisplacement of the actual mounting position from the scheduled mountingposition of the component 103 on the substrate 101 in the two mutuallyorthogonal direction (hereinafter referred to as “X-direction” and“Y-direction”) for each component 103. Then the mount inspector 14outputs the result as two numerical data along with data representingthe location of the inspected component 103.

The reflow furnace 15 heats the substrate 101, the solder 102, and thecomponents 103 and then cools them to solder the components 103 to thesubstrate 101. The soldering inspector 16 uses an AOI to inspect thestate of soldering between the substrate 101 and the components 103 andoutputs the inspection result as “soldering pass/fail data”. Forexample, the soldering inspector 16 outputs “OK” if the state ofsoldering is good, and outputs “NG” if it is defective. The solderinginspector 16 also outputs the location of the inspected component 103.

On the other hand, the process control system 3 includes a primaryrecorder 21, a data registration tool 22, a secondary recorder 23, andan SPC (statistical process control) tool 24. The primary recorder 21 isillustratively composed of a hard disk built in or connected to apersonal computer (not shown). The primary recorder 21 receives the scanresult of the QR code outputted from the two-dimensional barcodescanner, as well as the “printing quality data” outputted from thesolder print inspector 12, the “mounting quality data” outputted fromthe mount inspector 14, and the “soldering pass/fail data” outputtedfrom the soldering inspector 16 along with location information, andstores these data for a certain period. It is noted that the primaryrecorder 21 may be composed of a plurality of hard disks so as toreceive data in parallel. Then the input speed can be enhanced.

The data registration tool 22 is illustratively composed of a dataregistration program installed on a personal computer (not shown). Thedata registration program causes the computer to execute a procedure ofretrieving “printing quality data”, “mounting quality data”, and“soldering pass/fail data” from the primary recorder 21, a procedure ofcalculating “representative data” for each component 103 from the“printing quality data”, and a procedure of recording the“representative data”, the “mounting quality data”, and the “solderingpass/fail data” for each component 103 to the secondary recorder 23.

The calculation of “representative data” is performed by aggregatingnumerical data included in the “printing quality data” such as numericaldata representing the shape of the solder 102, e.g., height and volume,printed on the substrate 101 for each component 103 to which the solder102 is connected, to obtain statistics such as the average and standarddeviation for each component 103. The number of numerical datacorresponding to each component 103 is proportional to the number ofelectrodes corresponding to the component 103, and the number ofelectrodes corresponding to each component 103 depends on the type ofthe component 103. Hence the number of numerical data associated witheach component 103 depends on the type of the component 103. Thus the“representative data” is calculated for each component 103 as describedabove so that the quality of solder printing for the components 103 withdifferent numbers of electrodes can be represented by the same number ofnumerical values.

The secondary recorder 23 is illustratively composed of a hard diskbuilt in or connected to a personal computer (not shown) and records,for each component 103, the “representative data”, the “mounting qualitydata”, and the “soldering pass/fail data” inputted by the dataregistration tool 22.

The SPC tool 24 is illustratively composed of an SPC program installedon a personal computer (not shown). The SPC program causes the computerto execute a procedure of extracting the data of components 103 with the“soldering pass/fail data” indicating conforming (OK) from the datarecorded in the secondary recorder 23 to determine for each type ofcomponent 103 whether the condition of the solder printer 11 and themounter 13 needs adjustment.

For example, the average and standard deviation of the “representativedata” of a component 103 with the “soldering pass/fail data” being “OK”(hereinafter also referred to as “conforming item”) are obtained, and anupper and lower control bound are defined on the basis of the averageand standard deviation. Then, if the representative data of the heightof the solder 102 printed by the solder printer 11 falls outside therange between these control bounds (hereinafter referred to as “controlrange”), it is determined that the solder printer 11 needs adjustment.Likewise, control bounds are defined on the basis of the “mountingquality data” of conforming items, and it is determined with referenceto the control bounds whether the mounter 13 needs adjustment.

Furthermore, the SPC program causes the computer to execute a procedureof issuing an operation instruction to adjust the solder printer 11 inresponse to the determination that the solder printer 11 needsadjustment, and an operation instruction to adjust the mounter 13 inresponse to the determination that the mounter 13 needs adjustment.Moreover, the SPC program causes the personal computer to execute aprocedure of notifying an operator of these determination results viaelectronic mail or otherwise.

The above computer with the data registration program installed thereon,the computer that the hard disk constituting the secondary recorder 23is built in or connected to, and the computer with the SPC programinstalled thereon may be identical or different.

Next, a description is given of the operation of the electronic devicemanufacturing process 1 of this embodiment, that is, the method formanufacturing an electronic device according to this embodiment.

First, the operation of the surface mount line 2 is described.

FIG. 2 is a flow chart illustrating the operation of the surface mountline of this embodiment.

As shown in FIG. 1 and step S1 of FIG. 2, when a substrate 101 is fedinto the surface mount line 2, the two-dimensional barcode scanner 10scans the two-dimensional barcode (QR code) of the substrate 101 andoutputs the result to the primary recorder 21. Then the conveyor 17conveys the substrate 101 to the solder printer 11.

Next, as shown in step S2, the solder printer 11 prints paste solder 102on each electrode formed on the surface of the substrate 101. Then theconveyor 17 conveys the substrate 101 to the solder print inspector 12.

Next, as shown in step S3, the solder print inspector 12 inspects thesolder 102 printed on the substrate 101 and outputs the result as“printing quality data” to the primary recorder 21, which then recordsit. In an example, the solder print inspector 12 measures the shape,e.g., the height and volume, of the solder 102 formed on each electrodeof the substrate 101 and outputs the result as a set of numerical data.At this time, the solder print inspector 12 also outputs the location ofthe inspected region along with each set of numerical data. Then theconveyor 17 conveys the substrate 101 to the mounter 13.

Next, as shown in step S4, the mounter 13 mounts a plurality ofcomponents 103 on the substrate 101. Here, the mounter 13 mounts acomponent 103 for each location of the substrate 101 so that theelectrodes of the component 103 abut the solder 102. Then the conveyor17 conveys the substrate 101 to the mount inspector 14.

Next, as shown in step S5, the mount inspector 14 inspects the state ofthe component 103 mounted on the substrate 101 and outputs the result as“mounting quality data” to the primary recorder 21, which then recordsit. For example, the mount inspector 14 measures the amount ofdisplacement of the actual mounting position from the scheduled mountingposition in the X-direction and Y-direction for each component 103 andoutputs the result as a set of numerical data. At this time, the mountinspector 14 also outputs the location of the inspected component 103.Then the conveyor 17 conveys the substrate 101 to the reflow furnace 15.

Next, as shown in step S6, the reflow furnace 15 heats the substrate101, the solder 102, and the components 103 and then cools them. Thusthe solder 102 is once melted and then solidified so that the electrodesof the components 103 are soldered to the electrodes of the substrate101. Consequently, the components 103 are packaged on the substrate 101.Then the conveyor 17 conveys the substrate 101 to the solderinginspector 16.

Next, as shown in step S7, the soldering inspector 16 inspects, for eachcomponent 103, the state of soldering between the substrate 101 and thecomponent 103 and outputs data representing “OK” if the state ofsoldering is good and representing “NG” if it is defective as “solderingpass/fail data” to the primary recorder 21. At this time, the solderinginspector 16 also outputs the location of the inspected component 103,and the primary recorder 21 then records it. Thus an electronic device104 is manufactured.

Next, a description is given of the operation of the process controlsystem 3, that is, the process control method for the surface mount line2. This process control method constitutes part of the method formanufacturing an electronic device according to this embodiment.

FIG. 3A illustrates the format of data recorded in the primary recorder,and FIG. 3B illustrates the format of data recorded in the secondaryrecorder.

FIG. 4 is a flow chart illustrating the operation of the dataregistration tool of this embodiment.

FIG. 5 is a flow chart illustrating the operation of the SPC tool ofthis embodiment.

FIG. 6 is a graph showing a visualized example of process capability,where the horizontal axis represents operation shift, and the verticalaxis represents the amount of mounting displacement in the Y-direction.

As described above, in steps S2, S4, and S6 of FIG. 2, the primaryrecorder 21 shown in FIG. 1 receives and records “printing qualitydata”, “mounting quality data”, and “soldering pass/fail data”, eachalong with associated locations, from the surface mount line 2.Furthermore, the primary recorder 21 also receives and records the scanresult of the QR code. Here, an ID is formed from the scan result of theQR code and a string representing a location. A component 103 packagedon a location of a substrate is identified by this ID and the designdata of the electronic device 104. The primary recorder 21 stores thesedata in a prescribed folder for a certain period.

Here, the data format of the “printing quality data”, the “mountingquality data”, and the “soldering pass/fail data” is specified by theproperty of each data and the specification of each inspector. Forexample, as described above, the number of sets of numerical data foreach component 103 included in the “printing quality data” depends onthe type of the component 103. On the other hand, with regard to the“mounting quality data”, which represents the amount of displacement ofthe component 103, one set of numerical data exists for each component.With regard to the “soldering pass/fail data”, which representsconforming/defective for each component 103, one data originally existsfor each component 103. However, the soldering inspector 16illustratively outputs only the names of components for “NG”. Hence, asshown in FIG. 3A, the data format of the “printing quality data”, the“mounting quality data”, and the “soldering pass/fail data” is differentfrom each other. Furthermore, the number of lines in the “printingquality data” varies with components. Therefore, with these data left asthey are, it is difficult to associate the data with the components 103in a unified manner.

In this situation, the data registration tool 22 regularly monitors thefolder as shown in step S11 of FIG. 4. More specifically, the dataregistration tool 22 automatically accesses the primary recorder 21 at afixed time every day and monitors the data recorded in the above folderof the primary recorder 21. Then, as shown in step S12, the datarecorded in the primary recorder 21 is matched with a template of eachdata format of the “printing quality data”, the “mounting quality data”,and the “soldering pass/fail data” to discriminate the “printing qualitydata”, the “mounting quality data”, and the “soldering pass/fail data”from the data recorded in the primary recorder 21. By means of keywordsentered in each data such as keywords of the type of surface mount linesand apparatuses, the line and apparatus where these data have beencreated are discriminated. Next, as shown in step S13, the datadiscriminated in step S12 are extracted and retrieved along with the ID.

Next, as shown in step S14, the data are processed to calculate“representative data” for each component 103 from the “printing qualitydata”. For example, the height and volume of the solder 102 included inthe “printing quality data” are aggregated for each component 103 tocalculate statistics such as the average and standard deviation.

Next, as shown in step S15, the data are registered in the secondaryrecorder 23. More specifically, the “mounting quality data”, the“soldering pass/fail data”, and the ID retrieved from the primaryrecorder 21 in step S13 and the “representative data” calculated fromthe “printing quality data” in step S14 are recorded in the secondaryrecorder 23. In these data, as shown in FIG. 3B, the “representativedata”, the “mounting quality data”, and the “soldering pass/fail data”are associated with the component 103 identified by the ID.

Preferably, a plurality of tables are created in the secondary recorder23 for sequentially writing data in each table. Thus the data processingspeed can be enhanced by parallel processing.

On the other hand, as shown in step S21 of FIG. 5, the SPC tool 24 isalso regularly activated and accesses the secondary recorder 23. Then,as shown in step S22, from among the data recorded in the secondaryrecorder 23 (see FIG. 3B), the data of the components with the“soldering pass/fail data” being “OK” (conforming items) are extracted.

Next, as shown in step S23, the data extracted in step S22 are processedto create data for SPC determination and data for creating a graph. Forexample, from the extracted data, average X and standard deviation σ arecalculated for each type of components 103 with regard to the numericaldata such as the average height and the average volume of solder and theamount of displacement in the X-direction and the Y-direction at thetime of mounting to define control bounds inside the specificationbounds. For example, the upper control bound is set to X+3σ, and thelower control bound is set to X−3σ. The above numerical data areaggregated for each operation shift, for example.

Next, as shown in step S24, a graph is created on the basis of the dataaggregated in step S23. For example, as shown in FIG. 6, in the casewhere the component 103 is a connector, a graph is created in which theaverage (X), the upper dispersion (X+3σ), and the lower dispersion(X−3σ) for the amount of displacement in the Y-direction are plotted foreach shift. Thus the transition of process capability is visualized. Forexample, FIG. 6 demonstrates improvement in accuracy of mountingconnectors, as the maintenance of the mounter 13 is performed betweenthe shift B on date t and the shift A on date t+1.

Next, as shown in step S25, on the basis of the control bounds definedin step S23, it is determined whether the solder printer 11 and themounter 13 need adjustment. In the following, a specific determinationmethod is described. For the solder printer 11, with regard to theaverage and standard deviation of solder height and the average andstandard deviation of solder volume, the “pass ratio” is defined as theratio of instances falling within the range between the upper controlbound and the lower control bound (control range) versus the totalnumber of components processed by the solder printer 11, and it isdetermined whether this pass ratio falls below a target value. If thepass ratio is more than or equal to the target value, it is determinedthat the solder printer 11 does not need adjustment. However, if thepass ratio is less than the target value, it is determined whether theamount of solder is too large or too small on the basis of thestatistics of solder height and solder volume. For the mounter 13, themaximum and standard deviation of the amount of displacement in theX-direction and the Y-direction are compared with associated referencevalues for each type of components 103. If both the maximum and thestandard deviation exceed the reference values, it is determined thatthe mounter 13 needs adjustment.

If it is determined in step S25 that the solder printer 11 or themounter 13 needs adjustment, then as shown in step S26, an electronicmail is sent to the operator M, providing a notification that the solderprinter 11 or the mounter 13 needs adjustment, at the time of mountingthe target type of components 103. Furthermore, as shown in step S27, anoperation instruction is issued on a web page. The operation instructiondescribes the content of operations for decreasing or increasing theamount of solder printed by the solder printer 11, or the content ofoperations for adjusting the mounter 13.

In an example, the operation instruction for decreasing the amount ofsolder describes adjusting printing conditions such as printing speed,printing pressure, and clearance to within a prescribed control range,and checking the adhesion state of solder on the backside of the mask.The operation instruction for increasing the amount of solder describesadjusting the printing conditions to within a prescribed control rangeand checking the absence of residual solder on the mask. Furthermore,the operation instruction for adjusting the mounter describes checkingthe presence/absence of biting of components into the feeder set,checking the presence/absence of displacement of the sucking position,and checking the presence/absence of abnormal noise.

In response to receipt of the electronic mail, the operator M isinformed that the solder printer 11 or the mounter 13 needs adjustment,and can recognize the specific content of operations by checking theoperation instruction issued on the web page. Then the operator Madjusts the solder printer 11 or the mounter 13 as described in theoperation instruction, and thereby the printing state of solder or themounting state of components returns to good condition.

Thus the surface mount line 2, the data registration tool 22, and theSPC tool 24 operate in parallel. The process control system 3 collectsinformation about the intermediate and final quality of the electronicdevice 104 from the surface mount line 2 in operation, determines on thebasis thereof whether each apparatus constituting the surface mount line2 needs adjustment, and informs the operator of the determinationresult. Thus the operation of the surface mount line 2 can be providedwith feedback.

Next, the effect of this embodiment is described.

In this embodiment, the solder print inspector 12 inspects the solder102 printed by the solder printer 11 and outputs the result asquantitative numerical data. The mount inspector 14 inspects the stateof components 103 mounted by the mounter 13 and outputs the result asquantitative numerical data. The data registration tool 22 processesthese data. On the basis of the processed data, the SPC tool 24 candetermine whether the solder printer 11 or the mounter 13 needsadjustment. Thus, according to this embodiment, on the basis of theintermediate quality of products, it can be determined whether thesurface mount line needs adjustment. Consequently, even if the state ofmaterials such as the viscosity of solder paste changes, the apparatusescan be adjusted accordingly to make the quality of products stable andgood. Thus the process control can be provided with high accuracy.

According to this embodiment, among the data retrieved from the primaryrecorder 21 by the data registration tool 22, the “printing qualitydata” is used to calculate “representative data” for each component 103,and the “representative data” and the “mounting quality data” areassociated with the “soldering pass/fail data” and recorded in thesecondary recorder 23. Thus the SPC tool 24 can perform process controlon the basis of only the “representative data” and the “mounting qualitydata” of the components 103 with the “soldering pass/fail data” being“OK”. That is, the data of the components 103 with the “solderingpass/fail data” being “NG” can be excluded from the data group used asthe basis for process control. Consequently, noise data such as dataattributed to the inherent defect of the substrate is excluded, and onlythe data that can be controlled by apparatus and process conditions arecollected, so that a data group serving as the basis for process controlcan be established. Thus the process control can be provided with higheraccuracy.

In this embodiment, the SPC tool 24 defines a control range inside thespecification range and determines on the basis of this control rangewhether the apparatuses need adjustment. Hence measures can be takenbefore occurrence of electronic devices falling outside thespecification range, that is, defective items.

In this embodiment, when the SPC tool 24 determines that the solderprinter 11 or the mounter 13 needs adjustment, it issues an operationinstruction that specifically describes operations needed for adjustmentdepending on the direction of the adjustment. Hence the operator caneasily and rapidly perform adjustment operations. Adjustment operationsfor the solder printer, the mounter, and other apparatuses constitutingthe surface mount line often require considerable manpower. By issuingthe operation instruction as described above, the efficiency ofoperation does not depend on the operator's skill or know-how, andstable adjustment result can be obtained. Hence this embodiment achieveshigh stability and responsivity in process control.

According to this embodiment, the primary recorder 21 for receivingprimary data, that is, ID, “printing quality data”, “mounting qualitydata”, and “soldering pass/fail data” from the surface mount line 2, andthe secondary recorder 22 for retaining secondary data for processcontrol are separately provided. Thus the input operation for theprimary data and the SPC (statistical process control) using thesecondary data can be performed in parallel, and the processing speedcan be enhanced.

The invention has been described with reference to the embodiment.However, the invention is not limited to the embodiment. For example,addition, deletion, and modification of steps and apparatuses in theabove embodiment can be suitably made by those skilled in the art, andsuch variations are also encompassed within the scope of the inventionas long as they include the features of the invention.

For example, in this embodiment, the two-dimensional barcode scanner 10is provided at the most upstream position of the surface mount line 2 toscan a QR code before the printing step. However, in addition thereto,the QR code can be scanned also before the mount inspection step andbefore the soldering inspection step.

In this embodiment, the SPC tool 24 sends an electronic mail to alertthe operator to the need for apparatus adjustment, and posts anoperation instruction on the web to transmit the content of theoperation. However, the invention is not limited thereto. For example,notification of apparatus adjustment may be displayed on a displayscreen, and the operation instruction may be printed out each time fordocumentation.

In this embodiment, the primary data is illustratively obtained for allthe components. However, the invention is not limited thereto, but theprimary data may be sampled from selected components. For example, the“printing quality data” may be obtained only from some componentsselected from each cell, only from components with high defective rate,or only from components with large opening. In the case with a pluralityof mounters, the “mounting quality data” may be obtained from three toten components selected for each mounter and each mode of feedingcomponents. Thus, by obtaining data only from limited components, thedata processing speed can be enhanced, and the efficiency of processcontrol can be improved.

1. A process control method for a surface mount line including a solderprinter configured to print solder on a surface of a substrate, a solderprint inspector configured to inspect the printed solder and outputtingprinting quality data, a mounter configured to mount components on thesubstrate with the solder printed, a mount inspector configured toinspect a state of the mounted components and outputting mountingquality data, a reflow furnace configured to heat the solder to solderthe components to the substrate, and a soldering inspector configured toinspect a state of the soldering and outputting soldering pass/faildata, the process control method comprising: retrieving the printingquality data, the mounting quality data, and the soldering pass/faildata from a primary recorder with the printing quality data, themounting quality data, and the soldering pass/fail data recordedtherein, recording the printing quality data, the mounting quality data,and the soldering pass/fail data for each of the components in asecondary recorder; and determining whether the solder printer and themounter need adjustment by using the data of the components, which areassociated with the soldering pass/fail data recorded in the secondaryrecorder by a computer.
 2. The process control method according to claim1, further comprising calculating representative data for each of thecomponents from the printing quality data retrieved from the primaryrecorder, the recording includes recording the representative data asthe printing quality data in the secondary recorder.
 3. The processcontrol method according to claim 2, wherein the printing quality dataincludes numerical data representing a shape of the solder printed oneach electrode of the substrate, and the representative data includesstatistics obtained by aggregating the numerical data for each of thecomponents.
 4. The process control method according to claim 3, whereinthe statistics include an average and a standard deviation of thenumerical data.
 5. The process control method according to claim 1,wherein the determining further includes issuing an operationinstruction to adjust the solder printer in response to thedetermination that the solder printer needs adjustment, and issuing anoperation instruction to adjust the mounter in response to thedetermination that the mounter needs adjustment.
 6. The process controlmethod according to claim 1, wherein the determining includes; definingan upper control bound and a lower control bound for each type of thecomponents by using the data of the components with the solderingpass/fail data indicating conforming; and determining whether the solderprinter needs adjustment by using the upper control bound and the lowercontrol bound.
 7. The process control method according to claim 2,wherein the determining includes; defining an upper control bound and alower control bound for each type of the components by using the data ofthe components with the soldering pass/fail data indicating conforming;and determining whether the solder printer needs adjustment by using theupper control bound and the lower control bound.
 8. The process controlmethod according to claim 6, wherein the determining by using the uppercontrol bound and the lower control bound includes; defining a ratio ofinstances of which the representative data falls within the rangebetween the upper control bound and the lower control bound versus atotal number of the components processed by the solder printer; anddetermining in such a manner that, if the ratio is more than or equal toa target value, it is determined that the solder printer does not needadjustment and, if the ratio is less than the target value, it isdetermined whether the amount of solder is too large or too small on thebasis of the representative data.
 9. The process control methodaccording to claim 1, wherein the mounting quality data includes amountof displacement of a mounting position of the component from a scheduledmounting position of the component on the substrate.
 10. The processcontrol method according to claim 9, wherein the determining includesdetermining in such a manner that a maximum and a standard deviation ofthe amount of displacement are compared with associated reference valuesfor each type of the components and, if both the maximum and thestandard deviation exceed the reference values, it is determined thatthe mounter needs adjustment.
 11. The process control method accordingto claim 10, further comprising calculating representative data for eachof the components from the printing quality data retrieved from theprimary recorder, the recording includes recording the representativedata as the printing quality data in the secondary recorder.
 12. A dataregistration program for a surface mount line including a solder printerconfigured to print solder on a surface of a substrate, a solder printinspector configured to inspect the printed solder and outputtingprinting quality data, a mounter configured to mount components on thesubstrate with the solder printed, a mount inspector configured toinspect a state of the mounted components and outputting mountingquality data, a reflow furnace configured to heat the solder to solderthe components to the substrate, and a soldering inspector configured toinspect a state of the soldering and outputting soldering pass/faildata, the data registration program registering each of the data bycausing a computer to execute: retrieving the printing quality data, themounting quality data, and the soldering pass/fail data from a primaryrecorder with the printing quality data, the mounting quality data, andthe soldering pass/fail data recorded therein, recording the printingquality data, the mounting quality data, and the soldering pass/faildata for each of the components in a secondary recorder; and determiningwhether the solder printer and the mounter need adjustment by using thedata of the components, which are associated with the solderingpass/fail data recorded in the secondary recorder by a computer.
 13. Thedata registration program according to claim 12, further causing acomputer to execute calculating representative data for each of thecomponents from the printing quality data retrieved from the primaryrecorder, the recording includes recording the representative data asthe printing quality data in the secondary recorder.
 14. The dataregistration program according to claim 13, wherein the printing qualitydata includes numerical data representing a shape of the solder printedon each electrode of the substrate, and the representative data includesstatistics obtained by aggregating the numerical data for each of thecomponents.
 15. The data registration program according to claim 14,wherein the statistics include an average and a standard deviation ofthe numerical data.
 16. The data registration program according to claim12, wherein the determining further includes causing a computer toexecute issuing an operation instruction to adjust the solder printer inresponse to the determination that the solder printer needs adjustment,and issuing an operation instruction to adjust the mounter in responseto the determination that the mounter needs adjustment.
 17. The dataregistration program according to claim 12, wherein the determiningincludes causing a computer to execute; defining an upper control boundand a lower control bound for each type of the components by using thedata of the components with the soldering pass/fail data indicatingconforming; and determining whether the solder printer needs adjustmentby using the upper control bound and the lower control bound.
 18. Thedata registration program according to claim 13, wherein the determiningincludes causing a computer to execute; defining an upper control boundand a lower control bound for each type of the components by using thedata of the components with the soldering pass/fail data indicatingconforming; and determining whether the solder printer needs adjustmentby using the upper control bound and the lower control bound.
 19. Thedata registration program according to claim 17, wherein the determiningby using the upper control bound and the lower control bound includescausing a computer to execute; defining a ratio of instances of whichthe representative data falls within the range between the upper controlbound and the lower control bound versus a total number of thecomponents processed by the solder printer; and determining in such amanner that, if the ratio is more than or equal to a target value, it isdetermined that the solder printer does not need adjustment and, if theratio is less than the target value, it is determined whether the amountof solder is too large or too small on the basis of the representativedata.
 20. The data registration program according to claim 19, furthercausing a computer to execute calculating representative data for eachof the components from the printing quality data retrieved from theprimary recorder, the recording includes recording the representativedata as the printing quality data in the secondary recorder.